Abstract: A DC-DC converter includes independent first and second outputs to drive respective first and second loads from a common boost module. In one embodiment, a first linear regulator controls a first controlling device for the first output and a second linear regulator controls a second controlling device for the second output. The load requiring the higher voltage controls the boost module.

Abstract: A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.

Abstract: A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.

Abstract: A DC-DC converter includes independent first and second outputs to drive respective first and second loads from a common boost module. In one embodiment, a first linear regulator controls a first controlling device for the first output and a second linear regulator controls a second controlling device for the second output. The load requiring the higher voltage controls the boost module.

Abstract: A silicon integrated circuit includes a centrally located Hall element having an annular moat region surrounding the Hall element to isolate it from built in stresses in adjacent parts of the integrated circuit. The moat comprises at least one annular isolation wall, but preferably two concentric isolation walls. This moat construction also leads to a reduction in dependency of Hall element symmetry upon process variables.